scholarly journals Microfouling on biocidal and non-biocidal antifouling coatings

Author(s):  
Thirumahal Muthukrishnan ◽  
Sergey Dobretsov

Although antifouling marine paints have been used to prevent biofouling, not much is known about their effectiveness in preventing attachment of microorganisms. The current study aims at estimating the abundance of bacteria within biofilms developed on various commercial antifouling coatings in Marina Bandar Rowdha and Marina Shangri La, Oman. Coatings tested included Pettit #1863 and #1792, West Marine #11046620, #5566252 and #10175206, Hempel Hard Racing #76484, Hempel Olympic #86950, Hempasil X3 and International YBA920. All coatings were applied on clean plastic slides. Slides without any coating were used as controls. Microbial biofilms were harvested after 2, 7 and 14 days of biofouling. Bacterial density was estimated using epifluorescence microscopy. There was a significant difference between the various treatments (coatings and control) after 2, 7 and 14 days of biofouling. Although there were significant differences between both locations after 2 and 14 days of biofouling, no significant difference was observed after 7 days of biofouling at both locations. At Shangri La, the lowest bacterial density was found on International YBA920, Pettit #1792 and Hempasil X3 after 2 days, 7 days and 14 days respectively in comparison to the control treatments. However at Bandar Rowdha, International YBA920 showed the lowest bacterial density after 2 days while West Marine #10175206 showed the lowest bacterial density after both 7 days and 14 days of biofouling in comparison to the control treatment. The differential performance of tested antifouling coatings may be attributed to several factors including varying environmental conditions, difference in microfouling communities, time of exposure and physical and chemical properties of antifouling coating. 

2021 ◽  
pp. 1-10
Author(s):  
Anshu Siwach ◽  
Siddhartha Kaushal ◽  
Ratul Baishya

Abstract Mosses are one of the most important and dominant plant communities, especially in the temperate biome, and play a significant role in ecosystem function and dynamics. They influence the water, energy and element cycle due to their unique ecology and physiology. The present study was undertaken in three different temperate forest sites in the Garhwal Himalayas, viz., Triyuginarayan (Kedarnath Wildlife Sanctuary (KWLS)), Chakrata, and Kanasar forest range. The study was focused on understanding the influence of mosses on soil physical properties and nutrient availability. Different physico-chemical properties were analysed under two different substrata, that is, with and without moss cover in two different seasons, viz., monsoon and winter. We observed mosses to influence and alter the physical properties and nutrient status of soil in both seasons. All soil physical and chemical properties, except magnesium, showed significant difference within the substrates, among all the sites and across the two seasons. Besides the soil characteristics underneath the moss vegetation, the study also highlights the diversity of mosses found in the area. Mosses appear to create high nutrient microsites via a high rate of organic matter accumulation and retain nutrients for longer periods thus, maintaining ecosystem stability.


2021 ◽  
Vol 19 (1) ◽  
pp. 155-163
Author(s):  
S Sapkota ◽  
D Kc ◽  
H Giri ◽  
M Saud ◽  
M Basnet ◽  
...  

The present research was conducted on two factor Completely Randomized Design (CRD) with eight treatments and three replications. A set of experiments were carried out to evaluate the effect of postharvest ethephon treatment and packaging on ripening of mango cv. Maldah. The treatments consisted of ripening agent i.e., ethephon and control treatment under different packaging condition i.e., fiber with hole, fiber without hole, plastic with hole and plastic without hole. The result revealed that different packaging condition and ripening agents influenced the ripening behavior of mango. The highest TSS (15.26), sugar-acid ratio (23.66) and juice content (126.05) were recorded with fiber (without hole) and the lowest TSS (12.60), sugar-acid ratio (9.01) and juice content (116.05) with plastic (without hole). The highest TA (1.44) was recorded with plastic (without hole) and the lowest (0.66) with fiber (without hole). Similarly, the highest BT (2.83) was recorded with fiber (with hole) and the lowest (1.66) with plastic (without hole). Firmness, sweetness, TSS and juice content were the highest with the interaction effect of fiber bag (without hole) and ethephon treatment. In conclusion, mango fruits with ethephon treatment packed in fiber bag (without hole) enhances quality and ripening of mango whereas under controlled condition and without hole plastic packaging mangoes had low quality performance in terms of physio-chemical properties. SAARC J. Agric., 19(1): 155-163 (2021)


2016 ◽  
Vol 13 (1) ◽  
pp. 1-6
Author(s):  
Baghdad Science Journal

Soil invertebrates community an important role as part of essential food chain and responsible for the decomposition in the soil, helps soil aeration , nutrients recycling and increase agricultural production by providing the essential elements necessary for photosynthesis and energy flow in ecosystems.The aim of the present study was to investigate the soil invertebrates community in one of the date palms plantation in Aljaderia district South of Baghdad, , and their relationships with some physical and chemical properties of the soil , as Five randomly distributed replicates of soil samples were collected monthly. Invertebrates samples were sorted from the soil with two methods, direct method to isolate large invertebrates and indirectly to isolate small invertebrates using wet funnel method. The study also included the determination of physical and chemical factors of the soil (Temperature, Salinity, pH, Organic matter, Humidity, In addition to the soil texture).Monthly fluctuations in physical and chemical characteristics of the soil and the total invertebrates community study site were determined. Significant correlations the of the invertebrates community and each of temperature, organic matter, and humidity were observed. The study revealed that the temperature of the soil ranged between 5 to 25 C0 , The salinity concentration ranged between 1.1-1.9 ‰, The pH values ranged between 7.3 to 7.8 and the percentage of soil moisture ranged between 15 - 25% , Soil samples were composed of 44.6 % Clay, 19.7% Silt and 35.5% Sand.A total of 4625 individuals of soil invertebrates belonging to 16 taxa were sorted , within which the adult and larval insects were the most abundant, and from them 1283 individuals were sorted , represented 28% of the total numbers, followed by Isopoda , which 1030 individuals of them were sorted, In addition to Nematode, Oligochaetes Annelids family Enchytraeidae, and Earthworms family Lumbricida, Species of Chilopoda, Diplopoda, mites, land snails and slugs. The highest total individual number were recorded recorded durim moderate temperature months, February, March and April amounted to 838, 801 and 813 individuals, respectively.A significant correlation was mated between total number of soil invertebrates and each of temperature, organic matter and humidity. The significant difference in means was calculated according to LSD test.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11768
Author(s):  
Xuejiang Zhang ◽  
Dazhao Yu ◽  
Hua Wang

Pepper root rot is a serious soil-borne disease that hinders pepper production, and efforts are being made to identify biological agents that can prevent and control pepper root rot. Our group recently discovered and produced a biological agent, named G15, which reduces the diversity and richness of fungi and bacteria when applied to pepper fields. In the soil of the G15-treatment condition, the pathogenic fungus Fusarium was inhibited, while the richness of beneficial bacteria Rhodanobacter was increased. Also, the ammonia nitrogen level was decreased in the G15-treatment soil, and the pH, total carbon, and total potassium levels were increased. Compared to the control condition, pepper yield was increased in the treatment group (by 16,680 kg acre−1). We found that G15 could alter the microbial community structure of the pepper rhizosphere. These changes alter the physical and chemical properties of the soil and, ultimately, improve resistance to pepper root rot and increase pepper yield.


Author(s):  
Atef A. A. Sweed ◽  
Ahmed A. M. Awad

Low soil organic matter, low nutrient availability and the higher soil pH (more than 8) are the major problem of agricultural practices in region of Toshka. An incubation trial at October 2019 was conducted to investigate the effect of potassium humate (KH) and micronic sulfur (MS) on some chemical properties of different soils (sandy clay soils, loamy sand and sandy soils). The used amendments (KH and MS) were added to the studied soil at 4 levels of each amendment i.e. 0.0, 0.25, 0.50 and 1.0%. A two way randomized completely block design and provided with three replications. Studied parameters were included soil pH, EC, exchange Na and the content of available - P and K. Results showed that, the MS application at 1% level caused a significant decrease in soil pH values compared with the KH application and control treatment. These reductions were more pronounced in case of soil B (loamy sand). Also, KH application gave an increase on exchange Na and available-K. While MS application was cause an increased in soil EC and available-P in the three soils under study. Moreover, the increases in the percentage of available – K with added of KH were higher than added of MS for soils under study. While the percentages of available-P with added of KH were higher than with added of MS for studied soils. It may be recommended to add KH and MS at a rate of 1% to improve the soil chemical properties. But the effect of application from MS has greater than KH to increase dissolved sodium salts on the form of sodium sulfate, which facilitates disposal during soil drainage.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Lili Tang ◽  
Shaorui Nie ◽  
Wenhui Li ◽  
Chao Fan ◽  
Siqi Wang ◽  
...  

Abstract Background Wheat straw is a rich resource worldwide. Straw return is an effective strategy to alleviate soil-borne diseases on monoculture watermelon. Previous studies focus on soil structure, physical and chemical properties; however, little is known about the molecular responses on host plant. Results No significant difference on the population of Fusarium oxysporum f.sp. niveum race 1(Fon1) in rhizosphere soil was found between control (no addition of wheat straw) and the treated groups (addition of 1% (T1) or 2% (T2) wheat straw). RNA-Seq analysis showed that 3419 differentially expressed genes were clustered into 8 profiles. KEGG analysis revealed that phenylpropanoid biosynthesis and plant hormone signal transduction were involved in wheat straw induced response in monoculture watermelon. Genes in lignin biosynthesis were found to be upregulated, and the lignin and auxin contents were higher in T1 and T2 compared to the control. Lignin was also enriched and the Fon1 population decreased in watermelon roots treated with wheat straw. The enzyme activities of phenylalanine ammonia-lyase and peroxidase were increased. Conclusions Our data suggest that the addition of wheat straw enhances the defense response to Fon1 infection in watermelon through increasing lignin and auxin biosynthesis.


2020 ◽  
Author(s):  
Domina Delač ◽  
Paulo Pereira ◽  
Ivica Kisić

<p><strong>The effects of mulch (<em>Olea europea</em> and <em>Pinus halepensis</em>) on burned soils: A preliminary study in Adriatic coast (Croatia)</strong></p><p>Delac, Domina<sup>1*</sup>; Pereira, Paulo<sup>2*</sup>; Kisic, Ivica<sup>1</sup></p><p><sup>1</sup>University of Zagreb, Faculty of Agriculture, Department of General Agronomy, Svetosimunska cesta 25, 10000 Zagreb, Croatia. (*[email protected])</p><p><sup>2</sup>Mykolas Romeris University, Environmental Management Laboratory, Ateitis street 20, LT-08303, Vilnius, Lithuania (*[email protected])</p><p> </p><p>In the recent decades the frequency and intensity of summer drought periods is increasing in Adriatic coast. These changes in climate increase the vulnerability to wildfires. Wildfires can change soil physical and chemical properties. However, these effects can be mitigated by mulching. The aim of this work is to study the effects of mulch (<em>Olea europea</em> and <em>Pinus halepensis</em>) on fire affected soils. The wildfire occurred on 28 July 2019 and affected an area of about 900 ha in Dalmatia, near Adriatic Coast (43°45'06.0"N 15°56'02.9"E with an elevation of 105 m a.s.l.).  The mean annual temperature is 15.8 °C, and the annual precipitation is 800 mm. It was affected agricultural land with dominant culture <em>Olea europea</em> and abandoned grassing where dominates <em>Pinus halepensis</em>. Soils are classified as <em>calcocambisols</em>. Twenty-five days after the fire, two plots (5 treatments per plot) were established and covered with <em>Olea europea</em> and <em>Pinus halepensis</em> mulch. A control plot was established as well. Soil were sampled (0 – 5 cm), twenty- days after fire (August, 2019), before mulch application, and then 3 months after fire (November, 2019). A total of 15 samples were collected per treatment (45 each sampling date). The soil properties analysed were soil pH, soil organic matter (SOM), mean weight diameter (MWD) to express aggregate stability, and soil water repellency (SWR) measured with water drop penetration time method (WDPT) in different fractions (2 – 1 mm; 1 – 0.5 mm, 0.5 – 0.25 mm, and <0.25 mm). Soil pH was not significantly different among sampling dates and treatments. SOM was significantly different among sampling dates for <em>Olea europeae</em> treatment and control. <em>Olea europeae</em> treatment had a significantly higher SOM then <em>Pinus halepensis</em> and control treatment. MWD was significantly higher within <em>Olea europeae</em> treatment. Within <em>Pinus halepensis</em> and control treatment no significant difference was observed. The soil was classified as slightly water repellent (5 – 60 seconds) in <em>Olea europeae</em> soil finer fraction (0.5 – 0.25 mm and <0.25) in both sampling dates. In <em>Pinus halepensis</em> treatments and control, soil was wettable (<5 seconds), and no significant difference was observed among sampling date. Future sampling and analysis will be conducted during one year to estimate the effect of <em>Olea europeae</em> and <em>Pinus halepensis</em> mulch on soil properties.</p><p><strong>Keywords: </strong>Wildfire, <em>Olea europeae</em><strong>, </strong><em>Pinus halepensis</em>, mulch.</p><p> </p><p><strong>Acknowledgments</strong></p><p>This work was supported by Croatian Science Foundation through the project "Influence of Summer Fire on Soil and Water Quality” (IP-01-2018-1645).</p>


2021 ◽  
Author(s):  
Mohamed F. Ahmed ◽  
Mostafa A. Ibrahim ◽  
Ahmed S. Mansour ◽  
Ahmed N. Emam ◽  
Ashraf B. Abd El-Razik ◽  
...  

Abstract The present study evaluated the phytoremediation activities of Populus alba upon using nano metal-based-oxides (i.e., Fe2O3, ZnO, and Mn2O3-NPs) as analogues of three main heavy metals Fe, Zn and Mn exist in soil as micronutrients at three different concentrations (i.e., 20, 40, and 60 mg/L) compared to the control. The as-prepared nanoparticles have been prepared via co-precipitation method. In addition, the physico-chemical properties were investigated using transmission electron microscopy, Fourier transform infrared spectra, X-ray diffraction and dynamic light scattering techniques. Overall, a significant difference in the biomass production-related parameters such as fresh weight, shoot length, root length, and root number compared to control upon the treatment with micronutrients-based nano-metal-oxides (i.e., Mn2O3 > Fe2O3 > ZnO NPs, respectively), except a significant increase in the root number of Populus alba plant upon their treatment with ZnO NPs compared to other prepared nano-metal-oxides and control. Also, a remarkable increase in the chlorophyll index was monitored upon treatment with Fe2O3 than other used Mn2O3 and ZnO NPs, respectively. Moreover, RAPD-PCR bioassays were applied and the actual 6 primers showed a genetic variation percentage of 34.17% indicating that Populus alba is highly genetically stable even in a highly contaminated environment/soil. All these data enhance the idea of using the Populus alba plant in phytoremediation and heavy metal uptake as micronutrients to clean up the surroundings.


2019 ◽  
Vol 3 (1) ◽  
pp. 78
Author(s):  
Muhammad Irvan

Chikuwa is one of Japanese traditional fishery food product that commonly made from potato starch, fish surimi, and some spices. To enhance Chikuwa physical and chemical properties especially in texture attribute and protein content, Gelatin can be added. Gelatin is a partial hydrolysis protein that usually added in food making process to improve the gumminess quality and the protein content. Gelatin can be derived from bone collagen, skin and fish scale. The purpose of this study is to analyze the effect of gelatin from various skin fish to the physical and chemical characteristics of Chikuwa. The research method used is experimental laboratories using a completely randomized design (CRD) with 3 replications. The data analysed with ANOVA and continued with BNJ analysis if there is a significant difference between the treatments. This research has divided into two stages. The first step aim is to make the gelatin from the skin of seabass, payus fish and tilapia with 3% concentrations. The second step is Chikuwa making added with gelatin. The parameters that observed are water content, protein content, white degree, gel strength, sensory attributes, folding, bite. The results showed that Chikuwa with the addition of gelatin from seabass, payus and tilapia skin are significantly different (p <0.05) due to the physical and chemical characteristics of Chikuwa. The best Chikuwa quality is Chikuwa with the addition of seabass gelatin, where the gelatin yield is 18.03 ± 0.68; the gelatin gel strength is 251.11 ± 1.08 bloom; the viscosity is 5.80 ± 0.15 cP; the gel Chikuwa sample strength is 954.54 ± 0.56 gcm and protein content is 22.01 ± 0.98%


2016 ◽  
pp. 43-48
Author(s):  
Judit Horváth ◽  
Bence Mátyás ◽  
János Kátai

The soil is a natural resource, the fertility preservation is an important part of the sustainable development. We have to monitor the transformation dinamics of the organic nitrogen-containing substances, to get accurate information about the changes of the nitrogen cycle in the soil. Physical and chemical properties of the soil and the microorganism effect on the organic matter in the soil – in addition to the composition of organic matter. Wide variety of extracellular enzymes are present in this decomposition. These enzymes help in the transformation of the macromolecules to transforming low molecular weight compounds so they will be available during the assimilation. The urease enzyme, catalyzes the hydrolysis of urea to CO2 and NH3. The urease is widely spread in the nature, it is present in the microorganisms, plants and animals. We found that the soil moisture content, the rotation and the fertilization affect to the amount of urease in spring. Furthermore, we get significant difference between the irrigated and non irrigated samples in the second period of the year. Based on our results we can state that the activity of urease was higher in spring 2014. The objective of our study was to present how the different agronomic factors affect on the activity of urease in a long term fertilizationexperiment.


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